Firing mechanism for gun type casing perforators



Dec. 14, 1954 J. A. CONNOLLY FIRING MECHANISM FOR GUN TYPE CASING PERFORATORS Filed June 25 1951 2 Sheets-Sheet 1 14, 1954 J. A. CONNOLLY FIRING MECHANISM FOR GUN TYPE CASING PERFORATORS Filed June 23 1951 2 Sheets-Sheet 2 Z. 9 J y T. a Y. J J 5 J m M ,fiM l WW M .2 Mb 212-: a M E V l/ 4 1 4 m w a 0 i k 5 4 y j 4 l Z Z 2 2 Q 5 //7 47 W V I W2 a z Patented Dec. 14, 1954 FIRING MECHANISM FOR GUN TYPE CASING PERFORATORS John A. Connolly, Long Beach, Calif., assignor to Acme Tool & Tester Co., Ind, Long Beach, Caiifi, a corporation of California Application June 23, 1951, Serial No. 233,206

6 Claims. (Cl. 89-1) This invention relates to a novel firing mechanism for a gun casing perforator, in which the firing pin is released byrotation of the drill pipe on which the tool is run.

An ob ectormy invention is to provide a novel firing mechanism for gun type casing perr'orators in which the spring compressed firing hammer is held in cocked posit'lon and is released from this cocked position on rotation of the drill pipe.

A feature or my invention resides in the novel clutch construction between the casing engaging springs and the sleeve which depends from the body of the tool.

Still another ob ect of my invention is to so mount the casing engaging spring arms that they are free to rotate ndependently of the body of the tool until a desired point in the well is reached, at which time the spring arms are connected to the body of the tool and the entire tool is then fixed in position 111 the well casing.

Still another object of my invention is to provide a novel firing mechanism for easing perforators in which the fir-ing pin and all of the mechanism immediately abovfi this firing pin is kept dry when the tool is run into a we Still another feature of my invention is to provide a novel means of coupling the driving shaft with the actualtling :mandrel at the tmie that the tool is run into the W6 Other objects, advantages and features of invention may appear from the accompanying drawing, the subjoined detailed description and the appended claims.

in the drawing:

Figure 1 is a fragmentary side elevation of the lower portion of a tool upon which my firing mechanism is mounted.

Figure 2 is a side elevation of the casing engaging springs and showing these springs in locked position.

Figure 3 is a side elevation similar to Figure l with the exception that the clutch is shown in disengaged position.

Figure 4 is a fragmentary side elevation of the upper portion of the driving shaft.

Figure '5 is a longitudinal sectional view of the upper portion of my gun firing mechanism.

Figure 6 is a fragmentary longitudinal sectional view of the lower portion of my gun firing mechanism.

Figure 7 is an exploded view of the hanmier releasing mechanism.

Referring more particularly to the drawing, my gun firing mechanism 1 is run on an oil well tool, which has a shaft therein rotatable by the drill pipe on which the tool is suspended, such a tool is a formation tester, disclosed in Patent No. 2,197,078, issued April 16, 1940, and Patent No. 2,503,557, issued April 11, 1950, and a Well tester, Patent No. 2,005,955, issued June 25, 1935. Each of said patents includes the following structure: a body 2 from which a rotatable shaft 3 depends. This shaft is connected to the drill pipe upon which the tool is run and which is'not here shown but is shown in detail in each of the above mentioned patents. The body 2 is suspended in the well by means of slips 4, which engage the casing, these slips being mounted on a hanger 5, which is fixedly attached to the sleeve 6. The sleeve 6 surrounds the tube 7, which depends from the body 2 and is affixed thereto. The sleeve 6 can both rotate on the part 7 and also can'move vertically thereon. The means of holding the sleeve 6 against vertical movement is accomplished by the pin 8 which projects from the tube and this pin extends into the bayonet slot 9, all of this structure is shown and described in Patent No. 2,005,955, set forth above.

A plurality of spring arms 10 are attached to the spaced collars 11 and 12, and these collars are both rotatable and are vertically slidable on the sleeve 6. When the tool is being run into the well, the drill pipe will frequently rotate slightly and if the body 2 of the tool were held stationary against rotative movement, then the tool would be actuated due to this rotation of the drill pipe. Since this is undesirable, l have provided a means whereby the spring arrns 10, while tightly engaging the casing, will remain stationary as far as rotation is concerned, while permitting the tool body 2 as well as the tube .7, and the shaft 3 to rotate as much as may be necessary. When the point is reached where the tool is to be set, that is, where the slips 4 will be engaged with the wall of the casing, then the entire tool body 2 is lifted upwardly until the pro ecting pins 13 on the sleeve 6 will engage the lugs 14 on the bottom collar 12, thus acting as a clutch to engage the sleeve 6 with the spring arm assembly 10 and thereby holding the entire assembly stationary as far as rotation is concerned, due to the fact that the springs 10 are tightly engaging the casing. At this time, the slips 4 are also set by a means usual and well known in the art and then the body 2 cannot rotate and also .it cannot move vertically. When the body 2 of the tool .is held immovable, the shaft 3 can still be rotated by rotating the drill pipe which suspends the entire tool.

The shaft 3 extends a considerable distance below the tool body 2 and consequently i provide a set of spring centering springs 15 which should mount between the collars 16 and 1'7 and which engage the casing merely to center the entire tool and hold it central within the easing. The shaft 3 extends into the upper end of a long tubular housing 18 to the lower end of which a gun perforator 19 is mounted. This gun perforator is usual and well known in the art and the detailed construction thereof forms no part of this invention. A plurality of fuses 20 extend downwardly from the detonators 21 which are fired by the pin 22 mounted in the fitting 23 in the top of the gun perforator 19. Again, this construction of the detonators and firing pin is old and well known in the art and forms no part of this invention.

As previously stated, the shaft 3 extends into the top of the tubular housing 18 and rests against the ball bearing 24, which acts as a thrust bearing. A mandrel 25 fits within the shaft 3 and projects downwardly below this shaft. Packing 26 surrounds the mandrel 25 and thus prevents any fiuid from passing downwardly around this mandrel thereby keeping the entire pin firing mechanism dry. The bearing 24 also acts as a thrust bearing for the mandrel 25 since the upwardly extending sleeve 27 bears against the shoulder 28 on the mandrel. An internally threaded socket 29 is provided on the lower end of the mandrel 2S and this threaded socket terminates in a shoulder 30.

The firing control mechanism 31 as best shown in Fig. 7 consists of a cylindrical block 32 from which a coarsely threaded stem 33 rises. This stem threads into the socket 29, as shown in Figure 5. A plurality of spaced fingers 34 depend from the cylindrical block 32 and are preferably circular in cross-section or approximating this shape. A fitting 35 is mounted in the tubular housing 18 and is nonrotatable within this housing when the parts are assembled, as shown in Figure 6. This fitting is provided with a plurality of spaced holes 36 which are the same size and spacing as the fingers 34. A hammer 37 is mounted in the housing 18 above the firing pin 22 and is pressed downwardly by the spring 38. A pin 39 rises from the hammer 3'7 and extends upwardly through the fitting 35 and is slidable vertically within this fitting. A plurality of radially spaced lugs 40 are provided on the top of the pin 39 and these lugs again are so spaced and shaped that they will drop into the holes 36, as will be subsequently described.

When the lugs 40 are resting on top of the fitting 35, as shown in Figure 7, the spring 38 will be compressed and the hammer 37 will be raised ready to fire the pin 22. A set screw 41 engages the shaft 3 and is used during assembly of the tool. As soon as the tool is run into the well, the set screw 41 is removed. Also, at the time the tool is run into the well, a drive bolt 42 is inserted through the shaft 3 and through the upper end of the mandrel 25, substantially as shown in rigure 5. This bolt acts as a driving unit to couple the parts 3 and so that they will rotate together.

In operation, the tool is lowered into the well casing and as soon as the spring arms 10 engage the casing the sleeve 6 will move downwardly to disengage the pins 13 and the lugs 14. This permits the body 2 of the tool to rotate, if necessary, while the spring arms 10 can be non-rotative and merely slide downwardly while engaging the casing. As soon as the point is reached in the casing where the perforations are to be formed, the body 2 is pulled upwardly engaging the pins 13 and lugs 14, thus non-rotatably holding the tool. Thereafter, the slips 4 are set and the tool is now ready to fire.

Previous to running the tool in the well, the lugs 40 have been set on top of the fitting out of registry with the holes 36. The spring 38 is compressed and the hammer 37 is raised. With the tool set in the well, as previously described, the drill pipe is now rotated, this rotates the shaft 3 as well as the mandrel 25, through the coupling bolt 42. The threaded stem 33 now moves upwardly in the socket 29 until the shoulder 30 is reached and at this time the cylindrical block 32 will rotate with the mandrel 25. Before the threaded part 33 shoulders at 30, the fingers 34 have been withdrawn from the holes 36. Further rotation will now carry the fingers 34 against the lugs 40, thus rotating the pin 39 until the lugs 40 register with the holes 36, and at that time the lugs drop downwardly in these holes under the urge of the spring 38, which also forces the hammer 37 downwardly against the firing pin 22 and fires the casing perforator 19.

Having described my invention, I claim:

1. A firing mechanism for gun type casing perforators comprising a rotatable shaft, a tubular housing, said shaft extending into said housing, a hammer mounted for longitudinal movement in said housing, spring means engaging and pressing said hammer downwardly, a pin rising from the hammer, a fitting in said housing, latch means on the pin engaging the fitting, said latch means being releasable on rotation of said pin, a cylindrical block mounted on said shaft and in the housing, means on the cylindrical block slidably engaging the fitting, said means being disengageable from the fitting on vertical movement of the cylindrical block, threaded means coupling the cylindrical block and said shaft whereby the cylindrical block is first moved vertically relative to the shaft, and then rotated with the shaft, said threaded means comprising a mandrel depending from said shaft, intert engaging threads on the mandrel and cylinder block, said means on the cylindrical block engaging the pin to rotate the same on rotation of the cylindrical block to release the pin from the fitting.

2. A firing mechanism for gun type casing perforators comprising a rotatable shaft, a tubular housing, said shaft extending into said housing, a hammer mounted for longitudinal movement in said housing, spring means pressing said hammer downwardly, a pin rising from the hammer, a fitting fixedly mounted in the housing, said fitting having longitudinal slots therein, lugs on the pin slidable in said slots when in registry therewith, a cylinder mounted in the housing adjacent said fitting, pins depending from the cylinder and adapted to fit in said slots, a mandrel depending from said shaft, interengaging threads on the mandrel and cylinder whereby rotation of the mandrel will move the cylinder vertically, followed by rotative movement of the cylinder, said fingers engaging the pin to rotate the pin into registry with said slots in the fitting.

3. A firing mechanism for gun type casing perforators comprising a rotatable shaft, a tubular housing, said shaft extending into said housing, a hammer mounted for longitudinal movement in said housing, spring means engaging and pressing said hammer downwardly, a pin rising from the hammer, a fitting in said housing, latch means on the pin engaging the fitting, said latch means being releasable on rotation of said pin, a cylindrical block mounted on said shaft and in the housing, means on the cylindrical block slidably engaging the fitting, said means being disengageable from the fitting on vertical movement of the cylindrical block, threaded means coupling the cylindrical block and said shaft whereby the cylindrical blOCK is first moved vertically relative to the snatt and then rotated with the shaft, said threaded means comprising a mandrel depending from said shaft, interen' gaging threads on the mandrel and cylinder, said means on the cylinder engaging the pin to rotate the same on rotation or the cylinder to release the pin from the fitting, and a packing in said housing surrounding the mandrel to prevent leakage past said mandrel.

4. A firing mechanism for gun type casing perforators comprising a rotatable shaft, a tubular housing, said shaft extending into said housing, a hammer mounted for longitudinal movement in said housing, spring means pressing said hammer downwardly, a pm rising from the hammer, a fitting fixedly mounted in the housing, said fitting having longitudinal slots therein, lugs on the pin slidable in said slots when in registry therewith, a cylinder mounted in the housing adjacent said fitting, plus depending from the cylinder and adapted to lit in said slots, a mandrel depending from said shaft, interengaging threads on the mandrel and cylinder whereby rotation of the mandrel will move the cylinder vertically, followed by rotative movement of the cylinder, said fingers engaging the pin to rotate the pin into registry with said slots in the fitting, and a packing in said housing surrounding the mandrel to prevent leakage of fluid past said mandrel.

5. A firing mechanism for gun type casing perforators comprising a rotatable shaft, a tubular housing, said shaft extending into said housing, a hammer mounted for longitudinal movement in said housing, spring means engaging and pressing said hammer downwardly, a pin rising from the hammer, a fitting in said housing, latch means on the pin engaging the fitting, said latch means being releasable on rotation of said pin, a cylindrical block mounted on said shaft and in the housing, means on the cylindrical block slidably engaging the fitting, said means being disengageable from the fitting on vertical movement of the cylindrical block, threaded means coupling the cylindrical block and said shaft whereby the cylindrical block is first moved vertically relative to the shaft and then rotated with the shaft, said threaded means comprising a mandrel depending from said shaft, interengaging threads on the mandrel and cylinder, said means on the cylinder engaging the pin to rotate the same on rotation of the cylinder to release the pin from the fitting, and a packing in said housing surrounding the mandrel to prevent leakage past said mandrel, and a drive bolt extending through the shaft andthrough said mandrel whereby the shaft and mandrel are connected.

6. A firing mechanism for gun type casing perforators comprising a rotatable shaft, a tubular housing, said shaft extending into said housing, a hammer mounted for longitudinal movement in said housing, spring means engaging and pressing said hammer downwardly, a pin rising from the hammer, a fitting in said housing, latch means on the pin engaging the fitting, said latch means being releasable on rotation of said pin, a cylindrical block mounted on said shaft and in the housing, means on the cylindrical block slidably engaging the fitting, said means being disengageable from the fitting on vertical movement of the cylindrical block, threaded means coupling the cylindrical block and said shaft whereby the cylindricalblock is first moved vertically relative to the shaft, and then rotated with the shaft, said threaded means comprising a mandrel depending from said shaft, interengaging threads on the mandrel and cylinder block, said means on the cylindrical block engaging the pin to rotate the same on rotation of the cylindrical block to release the pin from the fitting, and a drive bolt extending through the shaft and through said mandrel whereby the shaft andmandrel are connected.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,169,559 Halliburton Aug. 15, 1939 2,305,139 Collins Dec. 15, 1942 2,388,938 Smylie Nov. 13, 1945 2,444,920 Davis et al July 13, 1948 

